$\left(x^4-7x^2-x-1\right)\left(x^4-3x^3-8x^2-3x-4\right)$

$400n^2-9a^2$

$\lim_{x\to13}\left(\:\left(\frac{2x-13}{x-13}\right)\right)$

$x^2-17x+60=0$

$\frac{2\log\left(x\right)}{\log\left(5x-4\right)}=1$

$\int\left(\frac{x^4+2x^3-3x+9}{2x}\right)dx$

$\frac{d}{dx}\left(3^{4x}.\log\left(x^2\right)\right)$